[PATCH for-next 4/4] nvme-multipath: add multipathing for uring-passthrough commands

[Christoph Hellwig]

Hmm, I'm a little confused on what this is trying to archive.

The io_uring passthrough already does support multipathing, it picks
an available path in nvme_ns_head_chr_uring_cmd and uses that.

What this does is adding support for requeing on failure or the
lack of an available path.  Which very strongly is against our
passthrough philosophy both in SCSI and NVMe where error handling
is left entirely to the userspace program issuing the I/O.

So this does radically change behavior in a very unexpected way.
Why?